First the code P1150 says "lack of O2 switches". This DTC is thrown when the PCM does not see any rich/lean changes from the O2 sensor even though the PCM has reached the fuel trim limit.
Consider this... If there were a problem with the fuel pressure sensor, wouldn't you expect it to affect BOTH banks?
However, the posted code applies to bank 2 (left side).
If this were my car, I would focus first on the things that would affect a single bank. Some examples include:
Bad O2 sensor or wiring.
exhaust leak on the left side.
Leak in the EGR system.
Valve cover gasket on the left side.
Stuck fuel injector on the left side (not as likely as one should also see a misfire DTC as well).
Once the above have been ruled out, then focus on the rest of the possible causes mentioned in the DTC (it's a long list).
I stole this from burns, hope that's ok
. Check these out.